Learning Objectives
- Safety measures should be taken when a seizure is witnessed
- The diagnostic work up should include blood tests, EEG and often MRI of the brain
- An isolated, single seizure may not require anticonvulsant treatment
History
A first year medical student is standing in a line waiting to get food at the cafeteria. She suddenly appears to stop speaking, she loses awareness, then she falls backwards, with arms flexed at the elbows. Her backpack and food tray fall from her hands. Her eyes are slightly open but they seem to be looking upwards. Her stiff arms appear to be flexed at the elbows and wrists and they are held against her chest. A crowd gathers around her. They are urged to step back to allow room. Another medical student turns her gently to one side. In about 60 seconds the tonic muscle movements cease. She seems tired. After 2 minutes, she begins to respond by voice and slightly opens her eyes. She has bitten her tongue and there is a small amount of bleeding. She is able to speak and stand after 5 minutes. She complains of a headache and she wonders what has happened.
Diagnosis
This is the scene of a first time seizure. A seizure is an uncontrolled loss of awareness with or without posturing or rhythmic motor activity. It is caused by aberrant electrical activity within the cerebral cortex. Seizures are often not seen in the clinic or the hospital. Sometimes, a patient with a first time seizure appears to stop breathing or turn blue. Seizures tend to last from 30-90 seconds. It is not necessary for patients with a seizure to be treated with CPR. Normally, breathing and consciousness return after a seizure, and there are rarely long term health effects.
When a seizure occurs in a public place, especially at a store or a school, the person with the seizure is often sent to the ER. This ensures that they obtain rapid testing for blood glucose and electrolytes. The next step in the evaluation of a first time seizure is neurology consultation, normally in an office setting.
Many different illnesses can cause a seizure. Some people have a tendency to have seizures. When a person has more than one seizure, they are considered to have epilepsy. Some types of epilepsies are severe and difficult to manage, others are mild and have a good prognosis. These conditions are referred to as primary epilepsies. Other causes of seizures include metabolic disorders, such as hyponatremia, side effects of medications, and processes that irritate the cerebral cortex, such as meningitis, neoplastic disease, stroke, cerebrovascular anomalies, and trauma. These are called secondary epilepsies. Sleep deprivation is also a factor in seizures. Patients undergoing EEG testing are sometimes asked not to sleep before their test to improve the chances of recording an abnormality.
When an adult has a first time seizure, the history and physical exam are helpful to determine how to take care of them. The account of a witness is important because patients who lose consciousness cannot remember what happened. Questions for the patient may be what were the circumstances of the seizure, was there a warning or unusual feeling after the seizure, if there were similar events in the past, and if there is a childhood or family history of seizures.
In the case of a first time seizure, medical tests are helpful because they will predict the chances of future seizures. They may also find the cause. These are blood tests, MRI of the brain, and EEG. The most helpful blood tests are complete blood count, electrolytes, and glucose. At times, others may help in certain situations. Prolactin is not a test that is helpful for diagnosing seizures. The blood tests are normally done the same day as the first seizure. An MRI of the brain is ideally done within one week or so, and an EEG is normally done around this time. These tests are not urgently needed if the patient has recovered to normal. For patients that have not recovered, these tests may be urgently needed (see for example the case describing status epilepticus). If two or more seizures have occurred, these tests are still helpful, but the tests would not be repeated after each seizure.
Treatment
For most patients with a first time seizure, there is less than a 50% chance that another seizure will occur in the next two years. If there is to be a second seizure, it tends to occur in the following 6-24 months. Although treatment is not necessary for everyone, medical treatment will reduce this risk of recurrence.
Test results also help predict the rate of recurrence. When either the neurological exam, the MRI of the brain or the EEG suggests there is a cause of the seizure, there is a good chance another seizure will occur (over 75%). In such a case medications should be prescribe. Patients who have normal test results have a lower risk of recurrence (30% in 4 years). About 90% of patients may become seizure free with treatment.
Seizures by themselves are rarely a danger to patients. Seizures are dangerous if they occur in certain settings, such as while driving a car, climbing a ladder, swimming or bathing. For that reason, patients with seizures are recommended not to do these activities until their seizures have been absent for at least six months. Different states and territories may have specific recommendations about driving after a seizure.
Medications are prescribed to patients that are likely to have more than 1-2 seizures. These medications are typically anticonvulsants, such as levetiracetam, lamotrigine, topiramate and phenytoin. There are many choices of anticonvulsants, and some of them are more effective for certain conditions than for others. Many adult patients with no prior medication history will do well with either levetiracetam and lamotrigine. Important side effects of these medications may be fatigue, emotional irritability, dizziness, and for lamotrigine, a severe rash that occurs when the medicine is provided in a large initial dose. These medications are normally prescribed in small doses at the onset and titrated to a higher dose if tolerated or needed. When a patient struggles with side effects or poor medication efficacy, a higher dose, different medication or additional medication may be used.
Most cases of genuine epilepsy will respond to 1-2 anticonvulsant medications. When patients are refractory to medical therapy, they may be a candidate for epilepsy surgery or the diagnosis of a nonepileptic condition may be considered.
Review Questions
- Tomorrow you witness a first time seizure in a stranger at the cafeteria. Wanting to help, and having learned how to handle this situation you:
a. Administer CPR to the patient
b. Ask to check blood sugar and electrolytes
c. Turn the patient to one side and quietly wait for 30-90 seconds
d. Vigorously shake the person to restore alertness
e. Explore the person’s belongings for possible causes of the event - Our medical student with a first time seizure visits a neurologist 4 days later. Her friend agrees to provide some details of the event during the meeting. She has a normal neurological exam, and later, normal blood tests, EEG, and MRI of the brain. She has no significant medical history. She asks whether she should use medication to prevent seizures, and what her chances of seizure recurrence are. You tell her that:
a. She is very likely to have another seizure, and she needs to start medication immediately
b. The answer to these questions is not known, since no studies are available to address this
c. She is not very likely to have another seizure, although medications could reduce the risk further
d. She is not likely to have another seizure, but she should take precautions to avoid accidents during the next several months
e. Both C and D - Later, our medical student has another seizure after she has stayed up late studying. She returns for a follow up visit, and as before, she has recovered to normal, and her exam is normal. This time, the right thing to do is to
a. Repeat the EEG study, to help see if changes have occurred
b. Repeat the MRI study
c. Start a medication, such as levetiracetam or lamotrigine
d. Inform her that her chances of recurrence are still low, since her tests are normal, and only a small number of seizures have occurred
e. Tell her she has a nonepileptic condition like pseudoseizures
f. Tell her this event was probably related to inadequate sleep, and that it would not occur in the future if she has enough sleep